1. Field of the Invention
The present invention deals generally with correcting the orientation elevation-wise of the headlights of a motor vehicle, notably of an automobile.
2. Description of the Related Art
In the case of the use of certain light sources such as xenon lamps, and, presently, light-emitting diodes for the headlights of automobiles, the regulation dictates an automatic correction of the inclination of the headlights in order for the latter not to risk dazzling the drivers travelling in the incoming direction. The correction must take account of the inclination of the vehicle on the road, as a function of its load.
These days, there are solutions in which a differential sensor measures the height difference between the rear axle and the front axle of the vehicle. The information is then supplied to a correction system. This solution works very well and allows for a dynamic correction of the inclination of the headlights. Nevertheless, it requires an adjustment at the end of the vehicle production line, once the headlights are fitted onto the vehicle. Furthermore, this solution remains costly and is incompatible with the possibility of subsequently equipping a vehicle which would not have such a functionality on leaving the factory.
To mitigate the above drawbacks, the applicant has focused on developing headlights, or assemblies comprising headlights, which are independent in relation to the functionality of inclination correction as a function of the load of a vehicle.
The choice was focused on the use of at least one sensor of accelerometer type to measure the general inclination of the vehicle and/or of the platform on which is mounted the lighting module whose inclination is to be controlled, preferably incorporated in at least one of the headlights of a pair of headlights, even in each headlight.
By using an accelerometer on the vehicle or in the headlight to be controlled, a real time measurement is obtained of the accelerations of the vehicle within the terrestrial reference frame. It is therefore possible to deduce therefrom the inclination of the vehicle or of the platform of the module creating the beam to be controlled according to the position of the sensor by a simple computation. Nevertheless, because the measurement is made in the terrestrial reference frame and not in a reference frame linked to the vehicle, this simple measurement incorporates all the vehicle inclination factors in a non-dissociated manner. In particular, it is impossible to know if the measured inclination of the vehicle is due to the gradient of the road, to the load of the vehicle or even to a combination of the two.